• Cardioversion is a medical procedure done to restore a normal heart rhythm for people who have certain types of abnormal heartbeats (arrhythmias).
  • Cardioversion is most often done by sending electric shocks to your heart through electrodes placed on your chest. Occasionally, your doctor may perform cardioversion using only medications to restore your heart’s rhythm.
  • Cardioversion is usually a scheduled procedure that’s performed in a hospital, and you should be able to go home the same day as your procedure. For most people, cardioversion quickly restores a normal heart rhythm.


  • Cardioversion procedures are usually scheduled in advance, although if your symptoms are severe, you may need to have cardioversion in an emergency setting.
  • You generally can’t eat or drink anything before the procedure. Your doctor will tell you whether you should take any of your regular medications before the procedure. If you do take medications before the procedure, sip only enough water to swallow your pills.
  • Before cardioversion, you may have a procedure called a transesophageal echocardiogram to check for blood clots in your heart, which can be dislodged by cardioversion, causing life-threatening complications. Your cardiologist will decide if you need a transesophageal echocardiogram before cardioversion.
  • For most people, cardioversion can quickly restore a regular heartbeat. For some, your irregular heart rhythm may return within a few minutes or days. It’s possible that you will need to have repeat procedures to keep a normal heart rhythm. You also may need to take medications to help maintain a normal heart rhythm.


  • A nurse or technician will place large patches called electrodes on your chest and sometimes your back. The electrodes will be connected to a cardioversion machine (defibrillator) using wires.
  • The defibrillator will record your heart rhythm throughout the procedure and will deliver shocks to your heart to restore a normal heart rhythm. This machine can also pace your heart if it beats too slowly after cardioversion.
  • Before the shocks are delivered, a nurse or technician will insert an intravenous (IV) line in your arm. The IV line is used to give you medications that will make you sleep during the procedure so that you won’t feel any pain from the shocks. Your doctor may also use the IV line to give you additional medications that can help restore your heart rhythm.
  • Once you’re sedated, electric cardioversion usually takes only a few minutes to complete.
  • Electric cardioversion is done on an outpatient basis, meaning you can go home the same day your procedure is performed. You’ll spend about an hour in a recovery room being closely monitored for complications.
  • Because you’ll be asleep for the procedure, your awareness of your surroundings may be affected afterward. You’ll need someone to drive you home, and your ability to make decisions may be affected for several hours after your procedure.
  • Even if no clots were found in your heart before your procedure, you’ll usually take blood-thinning medications for several weeks after your procedure to prevent new clots from forming. Some people may also be prescribed medications to help prevent future heart rhythm problems.


  • Complications of electric cardioversion are rare, and doctors can take steps to reduce your risk. Major risks of cardioversion include:
    • Dislodged blood clots: Some people who have arrhythmias have blood clots in their hearts.   Electric cardioversion can cause these blood clots to move to other parts of the body, which can cause life-threatening complications, such as a stroke. Your doctor may check for blood clots in your heart before cardioversion.
    • Abnormal heart rhythm: In rare cases, some people who undergo cardioversion end up with other heart rhythm problems during or after the procedure. If heart rhythm problems recur, your doctor can give you medications or additional shocks to correct the problem.
    • Low blood pressure: Some people experience low blood pressure after the procedure, which generally improves on its own and doesn’t need treatment.
    • Skin burns: Rarely, some people have minor burns on their skin where their electrodes were placed.
  • Before cardioversion, you may be given a blood-thinning medication for several weeks to reduce the risk of blood clots and stroke. Unless the episode of atrial fibrillation lasted less than 48 hours, you’ll need to take blood-thinning medication for at least four weeks before and after cardioversion to prevent a blood clot from forming even after your heart is back in normal rhythm.
  • There may be other possible risks. When you meet with your doctor, please ask questions to make sure you understand why the procedure is recommended and what the potential risks are.